Many fretted instruments (for example guitars, mandolins, banjos, and the like) are manufactured to be fitted with hard tempered steel core music strings. A high temper steel alloy, such as high-carbon steel, is usually utilized for the higher pitched or “unwound”, “plain” strings. The lower pitched strings commonly utilize a similar material as a core, with softer, more ductile material wire as a winding or wrap.
Over the years, string makers have experimented with a wide variety of alloys for the winding wire. Different alloys drawn to different tempers can produce tonal differences that are discernable to experienced musicians. The most popular and believed to be best-sounding strings are wound with a copper based, bronze alloy. Musicians have widely acclaimed the tone of phosphor bronze, 85-15 bronze, 90-10 bronze, and aluminum bronze, or 80-20 brass.
A conventional new copper based alloy string will have what musicians consider a bright, crisp, fresh tone. These are common descriptors of a string that produces a higher amplitude output when played; typically, the higher the amplitude, the “crisper” the tone. Within a matter of hours, the fresh tone of a new copper based alloy string will begin roll off. Depending upon a variety of conditions, such as the climatic conditions, the body chemistry of the musician, and playing style and frequency, a string could lose its crispness or go “dead” very quickly, or in some cases retain its desired tonal qualities for two to four weeks.
Copper based alloys, left unprotected and exposed to ambient air, begin to oxidize quickly. The added effects of moisture caused by human perspiration speed the oxidation process, further causing the string to lose its brilliance.
An effective solution known in the art for delaying oxidation and loss of freshness is to coat the copper based winding wire or the entire wound string with a polymer material. Winding wires are often coated with urethane, enamel, epoxy or other suitable polymeric material. Finished wound strings coated with polytetrafluoroethylene (PTFE) or other polymers provide effective protection to degradation due to oxidation of copper. Both solutions improve how long the new string will retain its original tonal characteristics, although the original tonal sound of a polymer coated string is dampened relative to a new uncoated string.
Unfortunately, the introduction of any flexible, polymeric material such as those described above creates acoustical damping that diminishes the crispness in tone of the new string. The coating, whether on the winding wire or the finished wound strings, will reduce the output of the upper partial harmonics. It would be useful to have a musical instrument string that exhibits crisp tones comparable to an uncoated string, while retaining the original tonal crispness for a longer duration, comparable to a polymer coated string.